This is implemented via touching a file on stop as a hook in the systemd
unit. The ctime of this file is then used to get the `finishedAt` time
in the future.
In addition, this changes the `startedAt` and `createdAt` to use the api
server's results rather than the annotations it previously used.

It's possible we might want to move this into the api in the future.

Fixes #23887